Won't shift into overdrive when cold

[Joe Doherty]

My 2002 Explorer Sport won't shift into overdrive when cold. I have to drive about 4 to 5 miles when very cold before it will shift into OD. This is most anoying when you are doing 60 and the engine is reving at about 3 grand. I have tried taking my foot off the acellerator and it still won't shift into OD. Is this normal or do I have a problem? This seems to happen when temperatures are below 15 F.

 

[Opera House]

As part of the emissions system, the computer will not allow you to go into OD untill the engine is fully warmed up.